26 March 2019

Reducing Age-Related Language Decline

Welcome back. Do you ever experience tip-of-the-tongue lapses, when you just can’t recall a word you know? By the time you reach my age, you’ve learned so many words, it can be difficult to remember them all as quickly as you’d like; but there’s more to it.

An international team led by researchers from the UK’s University of Birmingham demonstrated that, while cognitive abilities decline with age, aerobic fitness can reduce those tip-of-the-tongue occurrences.

Before describing the study, I’d better point out that tip-of-the-tongue states are not a memory problem; they’re not associated with memory loss. They indicate a disruption in the two-stage process of retrieving the word meaning and phonology (sound form representations).

Language ExperimentFor the language experiment, young and old participants completed the same computer-based, definition-filling task. The participants were presented 60 definitions or questions in random order (20 definitions of low frequency words, 20 definitions of easy words and 20 questions about famous people).

The definitions and questions remained on screen until the participants responded that they knew the target word, did not know the target word or had a tip-of-the-tongue experience. (The instructions read: “Usually we are sure if we know or don’t know a word. However, sometimes we feel sure we know a word but are unable to think of it. This is known as a ‘tip-of-the-tongue’ experience.”)

If participants indicated they experienced a tip-of-the-tongue state, they were asked to provide three pieces of information about its sound: (1) the initial letter or sound; (2) the final letter or sound and (3) the number of syllables. Finally, participants were asked to select the target word from a list of four words displayed on the screen or to indicate that the word they were thinking of was not in the list.

The data were analyzed using mixed effects models, an extension of linear regression models. In addition to comparing older with younger participants, the researchers performed a median split on the standardized aerobic fitness scores to generate a high-fit older adults group and a low-fit older adults group.ResultsThe key findings were that older adults experienced more tip-of-the-tongue occurrences and had less access to phonological information than did the younger participants; however, the more aerobically fit the older adults were, the less likely they were to experience a tip-of-the-tongue state.

The study also found that young and older adults both experienced fewer tip-of-the-tongue occurrences the shorter the target words (as measured by the number of phonemes) and the larger their vocabulary size. Notably, older adults had a significantly larger vocabulary than young participants.Wrap UpOverall, the study demonstrated that there is a relationship between language production abilities and aerobic fitness in healthy older adults. The higher the older adults’ aerobic fitness level, the lower the probability of experiencing a tip-of-the-tongue. The results further support increased physical activity for healthy aging and optimal brain function across the life span. Go for it!